Trying to use double_registers for fetching single precision fp values creates
four different implementations of this method depending on the architecture, hence
separating them out into their respective folder.


Change-Id: Ide61fe2e7a95bd8427b377959b262633d8c57e61
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1730663Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Milad Farazmand <miladfar@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#63042}